Fuel Line routing?

[TurboJ]

Less pressure means less cause for leaks.

I am not kidding. Think about how the system works and you'll see what I mean.

[CarlosA]

I think it also gives the system an opportunity to bleed off some of the air that never leaves - i`ve been running clearish lines with the return route and have no bubbles in return lines for the first time.

[ORCoaster]

Would less pressure to the #1 or balanced pressure on both sides, 1 and 4 make it clack less?

[fatmobile]

 I've been putting a "T" between the end lines.
 Mostly because I don't like,... or often can't find one of the end plugs.

 It allows new options for routing to the return banjo without hitting the accelerator stuff.

[TurboJ]

I don't know about this affecting the clacking noise, but trying this design can't hurt.

The comment about air escaping the return lines more easily is true.

About my comment on the extra banjo fitting: If you have a new banjo bolt and connectors, and new copper washers in there,
leaks will always happen in the rubber/silicone hoses before the banjo fittings. Those same banjos are used on EFI fuel
systems where regular fuel hoses simply burst clean in half by the pressure. So, adding a new banjo connector is not a risk by any means.

The problem with the stock arrangement is that the plugged #1 injector has to vent the overflow fuel through three other injectors (in all of which there is pressure) before it gets to the return line. #2 and #3 suffer from this same phenomenon, although less.

If you wanted to build a faultless, optimal system, you would have eight separate returns connecting straight to the fuel tank.
Obviously this would be stupid and complete overkill, but small improvements of the venting system will eliminate leaks, and help bleed
out the air much better.

[Gizmoman]

Great explanation - makes sense to me now - thanks much.
Do you have a source for the dual banjo?

[TurboJ]

Any hydraulics shop or a shop that carries automotive fuel system components.

Something like this should work:

http://www.blundellspeed.com/images/products/banjo_fitting_hose/double_banjo_fitting_hose.jpg

[ORCoaster]

That is a double for the larger return line to the tank is it not?  The dual banjo on the out bolt has two different sizes for return line to pump from injectors and out to fuel tank.  You just need a tee like mentioned earlier on the little hoses.

[libbydiesel]

There is never any pressure at all in any of the injector jumper hoses unless there is a restriction in the return hose to the tank.  The flow is completely free between the two injector barbs of an injector and the amount of fuel that flows from the barbs is so little that the hose size is more than enough to flow it without building any pressure.

[mtrans]

x2
On my Fiat I have 50 ml of fuel for 30 minutes,I have separated line from OUT bolt and injectors for this check.

[R.O.R-2.0]

...and if you want to make sure there's the least possibility of leakage, I suggest twin return lines; i.e. from both ends of the injector bank.
Then just fit a Y-connector between them and the return port on the pump.

Wow, I never thought of that. I think I'll try it.

i have a cap on injector 1, and injector 4

and the line between injectors 2 & 3, has a T in it, and then from there, to the inlet..

i have 3 injector jumper lines, and the middle line is split with a T in the middle.. makes it look much more clean.